A well-known procedure is the dental restoration of a partially or wholly edentulous patient with artificial dentition. Typically, a dental implant is seated into the bone of a patient's jaw. The dental implant includes a socket, e.g., a bore, which is accessible through the overlying or surrounding gum tissue for receiving and supporting one or more attachments or components which, in turn, are useful to fabricate and support prosthodontic restorations. The dental implant generally includes a threaded bore to receive a retaining screw for holding mating components therein. Dental implant procedures may use a variety of implanting modalities, for example, blade, threaded implant, or smooth push-in implant.
Single tooth restorations present the unique requirement that the prosthesis must be supported non-rotationally when engaged with the implant. Often times this is achieved through non-rotational support of the underlying abutment. When a prepared natural tooth is the underlying abutment, this requirement is met in the normal course of preparing the abutment with a non-circular cross-section. Likewise, when the underlying abutment is a post fitted onto an implant, this requirement is met by preparing the post with a non-circular cross-section. This latter scenario may be more complicated due to the added connection between the implant and the abutment.
While numerous design iterations have been marketed, overall there have been three generations of the implant-abutment interface within these assemblies: an external hex implant, an internal connection implant, and a vertical connection assembly. The external hexagonal implant design has a hexagonal shape (or another anti-rotation feature) protruding out of the implant and the corresponding prosthesis has a female hexagonal receptacle. There is a surface below the hexagonal protrusion on which the abutment is seated. The hexagonal protrusion acts to constrain the abutment from rotating around the longitudinal axis as well as preventing movement on the plane coincident with the implant seating surface. A screw is introduced and rotated to attach the abutment and the implant. The screw is essentially the sole component resisting bending forces.
Unfortunately, screws are a separate component that must be installed in the implant in addition to the abutment during oral surgery. Screws are small and difficult to deliver into a patient. The size of the screw makes it difficult to hold when inserting the screw into the implant and abutment and runs the risk of being ingested, or even worse, aspirated, if the screw is dropped. Further, a normal screw has a head that sits above the seating surface of the implant. The head limits the degree of angle adjustment of the abutment because the abutment screw head breaks out from the body once a certain angle is achieved, depending on the physical characteristics of the screw (i.e., screw head height and diameter), the location of the screw head, and the angle of the abutment. In order to accommodate a screw (or at least a diameter equivalent to the screw head diameter), the access hole in the abutment must be sized to accept the largest diameter of the screw, and this can often be relative large (compared to the outer diameter of the abutment. This can weaken the structural stability of the abutment, as well as potentially detract from the ultimate aesthetics of the provisional and/or final restoration(s)
Thus, there is a need for a retention component between a dental implant and a mating component such as an abutment that allows the attachment of the implant and the abutment without using a conventional mounting screw. There is a further need for a retention component that is pre-seated in an implant thereby preventing the mishandling of a screw within the oral cavity during oral surgery. There is a further need for an interface between a dental implant and abutment that creates a seal between the two components, thereby preventing and potentially promoting bacterial exchange between the oral cavity and the internal aspect of the implant. There is a further need for an interface between a dental implant and an abutment that allows design flexibility of a restoration having the possibility of an extremely short and/or highly angled restoration without sacrificing strength and/or aesthetics of the restoration.